A Researcher Has Developed a Set of Breathing Exercises and Would

A researcher has developed a set of breathing exercises and would like to investigate whether they can help to reduce anxiety.She designs an experiment as follows.She will obtain a group of volunteers suffering from anxiety.They will be given a test to measure the level of their anxiety.Volunteers will be randomly assigned to one of three groups.Those in group 1 will do breathing exercises for 15 minutes per day,those in group 2 will do breathing exercises for 30 minutes per day,and those in group 3 (control group)will do no breathing exercises.After a suitable time period,each person will again take the anxiety test.The researcher will compare the average change in score for the three groups.Is it possible to double blind this experiment? Explain.